双向流固耦合实例(Fluent与structure)
fluent流--固耦合传热-图文
![fluent流--固耦合传热-图文](https://img.taocdn.com/s3/m/4136031f11a6f524ccbff121dd36a32d7375c7b2.png)
fluent流--固耦合传热-图文一两端带法兰弯管置于大空间内,管外壁与空气发生自然对流换热;内通烟气并与管内壁发生强制对流换热。
结构和尺寸及其它条件如图。
计算任务为用计算流体力学/计算传热学软件Fluent求解包括管内流体和管壁固体在内的温度分布,其中管壁分别采用薄壁和实体壁两种方法处理。
所需的边界条件采用对流换热实验关联式计算。
要求在发动机数值仿真实验室的计算机上完成建立几何模型、生成计算网格、建立计算模型、提交求解、和结果后处理等步骤,并分别撰写计算任务的报告,计算报告用计算机打印。
计算报告包括以下与计算任务相关的项目和内容:(1)...............................传热过程简要描述包括传热方式、流动类型等;(2)计算方案分析包括所求解的控制方程及其简化、边界条件及其确定方法和主要计算过程;(3)计算网格简报包括网格划分方案、单元拓扑、单元和节点数量、网格质量等;(4)计算模型描述包括流体物性、边界条件、湍流模型、辐射模型及近壁处理等;(5)求解过程简报包括求解方法、离散格式、迭代过程监控、收敛准则等;(6)................................................计算结果及分析给出下列图表和数据:纵剖面和中间弯管45°方向横剖面上的温度、温度梯度、速度分布图,以及法兰和中间弯管处的局部放大图。
管内壁面上的温度、热流密度和表面传热系数分布,包括三维分布和沿管长度方向上的分布。
............................................................ .........................................总热流量。
由2种数值计算方法求得管内外烟气和空气之间换热的平均传热系数和烟气出口温度,并与工程算法得到的数值对比。
1、传热过程简述计算任务为用计算流体力学/计算传热学软件Fluent求解通有烟气的法兰弯管包括管内流体和管壁固体在内的温度分布,其中管壁分别采用薄壁和实体壁两种方法处理。
「耦合案例」双向流固耦合(2)
![「耦合案例」双向流固耦合(2)](https://img.taocdn.com/s3/m/dad6a7ff846a561252d380eb6294dd88d1d23d56.png)
「耦合案例」双向流固耦合(2)4 Mechanical求解设置4.1 材料参数定义双击模型树节点B2进入材料定义面板如下图所示,添加新材料Rubber,设置其密度为1100 kg/m3,设置杨氏模量1e7 Pa,泊松比为0.45关闭材料定义面板4.2 网格划分鼠标双击B4单元格进入Mechanical右键选择模型树节点Geometry > FFF\Solid,点击弹出菜单项Suppress Body删除流体区域几何右键选择模型树节点Mesh,点击弹出菜单项Insert → Method插入网格方法属性窗口中设置Method为Sweep,如下图所示指定Source为圆环面,指定Number of Divisions 为100右键选择模型树节点Mesh,点击弹出菜单项Insert → Face Meshing属性窗口中设定Geometry为如图所示的圆环面,指定该面采用映射网格划分右键选择模型树节点Mesh,点击弹出菜单项Insert → Sizing添加网格尺寸属性窗口指定圆环面网格尺寸为1 mm,并设定Behavior为hard右键选择模型树节点Mesh,点击弹出菜单项Generate Mesh生成网格,最终形成网格如下图所示4.3 计算参数定义鼠标选中模型树节点Analysis Settings,属性窗口中设置Step End Time为2 s,设置Auto Time Step为Off,设置Define By为Substeps,设置Number of Stepping为1注意:这里设置的Step End Time值必须大于耦合计算的时间。
真正耦合计算的时间在System Coupling中指定,但指定值必须小于此处的Step End Time值。
鼠标选中模型树节点Transient,图形窗口中选择管道内表面,点击鼠标右键,选择弹出菜单项Insert → Fluid Solid Interface指定该面为流固耦合面选择管道的两个圆环端面,点击鼠标右键,选择弹出菜单项Insert → Fixed Support指定两个面为固定约束在Solution节点上指定后处理内容,如查看等效应力、等效应变、位移等物理量。
(整理)FLUENT14双向流固耦合案例.
![(整理)FLUENT14双向流固耦合案例.](https://img.taocdn.com/s3/m/d24ccb480066f5335a8121fe.png)
说明:本例只应用于FLUENT14.0以上版本。
ANSYS 14.0是2011年底新推出的版本,在该版本中,加入了一个新的模块System Coupling,目前只能用于fluent与ansys mechanical的双向流固耦合计算。
官方文档中有介绍说以后会逐渐添加对其它求解器的支持,不过这不重要,重要的是现在FLUENT终于可以不用借助第三方软件进行双向流固耦合计算了,个人认为这是新版本一个不小的改进。
模块及数据传递方式如下图所示。
一、几何准备流固耦合计算的模型准备与单独的流体计算不同,它需要同时创建流体模型与固体模型。
在geometry模块中同时创建流体模型与固体模型。
到后面流体模型或固体模块中再进行模型禁用处理。
模型中的尺寸:v1:32mm,h2:120mm,h5:60mm,h3:3mm,v4:15mm。
由于流体计算中需要进行动网格设置,因此推荐使用四面体网格。
当然如果挡板刚度很大网格变形很小时,可以使用六面体网格,划分六面体网格可以先将几何进行slice切割。
这里对流体区域网格划分六面体网格,固体域同样划分六面体网格。
二、流体部分设置1、网格划分双击B3单元格,进入meshing模块进行网格划分。
禁用固体部分几何。
设定各相关部分的尺寸,由于固体区域几何较为整齐,因此在切割后只需设定一个全局尺寸即可划分全六面体网格。
这里设定全局尺寸为1mm。
划分网格后如下图所示。
2、进行边界命名,以方便在fluent中进行边界条件设置设置左侧面为速度进口velocity inlet,右侧面为自由出流outflow,上侧面为壁面边界wall_top,正对的两侧面为壁面边界wall_side1与wall_side2(这两个边界在动网格设定中为变形域),设定与固体交界面为壁面边界(该边界在动网格中设定为system coupling类型)。
操作方式:选择对应的表面,点击右键,选择菜单create named selection,然后输入相应的边界名称。
ANSYSWorkbenchFluent流固耦合传热及热结构分析学习教案
![ANSYSWorkbenchFluent流固耦合传热及热结构分析学习教案](https://img.taocdn.com/s3/m/c12532af3c1ec5da51e2702d.png)
会计学
1
第一页,共7页。
以前本人发了一个贴子,关于Fluent 计算的 温度如 何传递 到结构 网格上 ,该方 法已经 过时, 由于AN SYS Workbench功能的日益强大,建议 使用更 好、更 简便的 方法。 案例(àn lì)如下: 1 打开Workbench,tool box/component systems里选mesh,空白区出现如下图,然后双击Geometry,导入几何模型,这是一个外部固体包裹内部管流的简单(jiǎndān)模型,仅用于演示步骤。任选一个Part, 在Details of Body里有个选项Fluid/Solid,需要分别定义好流体和固体
第5页/共7页ቤተ መጻሕፍቲ ባይዱ
第六页,共7页。
6 添加约束,计算。 这仅是个简单演示,具体(jùtǐ)问题还 要涉及 到定义 材料塑 性应力 应变数 据,分 析的非 线性设 置,接 触的设 置等等 。
第6页/共7页
第七页,共7页。
Named selections命令分别创建 Inlet, outlet和wallout. Wallout用来定
义固体外表面与环境的对流换热边界条件
第2页/共7页
第三页,共7页。
3 关闭Meshing 窗口返回到project schematic界面,右击Mesh→Transfer Data To New → Fluent, 将建立Fluent的分析项目。 此时Mesh后面变为闪电(shǎndiàn)符号,需右击它再点菜单中update
双击Setup,打开Fluent窗口,设置材 料(cáili ào)、流 相固相 、激活 能量方 程、湍 流模型 、边界 条件等 。进口 流速1m/s, 600K, 出口0pa,wallout定义对流换热系 数5, 环境温 度300K。
(完整版)利用FLUENT软件模拟流固耦合散热实例
![(完整版)利用FLUENT软件模拟流固耦合散热实例](https://img.taocdn.com/s3/m/07433053e2bd960591c67728.png)
Symmetry Planes
Air Outlet
Electronic Chip (one half is modeled) k = 1.0 W/m∙K Q = 2 Watts
Circuit board (externally cooled) k = 0.1 W/m∙K h = 1.5 W/m2∙K T∞ = 298 K
在Scale Grid菜单中,选择Grid was created in inch, 点击 change length units, 然后再点击 Scale, 得到正确 大小的计算区域。
3 . 选择求解器,物理模型 ① Define—Model--Solver
② Define—Model--Energy
7.用体相分割,得到流体区域Volume 2
Volume 2 split with volume 3
Volume 2
Volume 3
划分网格
1.将chip边划分为15*7*4
7 4
15
2.划分其他边的网格
8 16 16
44
100 100
8
16
16 4
划分数:
Board沿Y向边: 4 Board沿Z向边: 8 Fluid 沿Y向边: 16 沿X方向长边: 100
⒊
在Solid面板中,勾选Source Terms,然后选择Source Terms菜单,点击Edit,进入Energy面板,将数值设为1, 菜单将扩展开来,从下拉选项中选择constant, 然后将前面数值设定为904000,然后确认OK。
④ 指定速度入口条件
在Boundary Conditions面板中,Zone下面选择inlet, 确认Type下为velocity-inlet,点击Set进入到Velocityinlet面板中,在velocity specification method右边选 择Magnitude and Direction, 菜单展宽。 在Velocity Magnitude后面输入1, 在x-Componen of Flow Direction后面输入1,其他方向保持为0。表 示air流体沿x方向以1m/s的大小流动。 选择Thermal 菜单将Temperature设定为298K。
fluent流固耦合案例
![fluent流固耦合案例](https://img.taocdn.com/s3/m/e96cbc3078563c1ec5da50e2524de518974bd340.png)
fluent流固耦合案例
一个常见的流固耦合案例是风洞实验。
风洞是一个用于模拟飞行器在风场中运动的设备,其中飞行器模型放置在流场中,通过控制风洞内的气流运动来模拟不同飞行状态下的飞行器性能。
在风洞实验中,流体(空气)和固体(飞行器模型)之间存在耦合关系。
流体流动会受到飞行器模型的阻力、升力等力的影响,同时飞行器模型的形状、表面特性也会影响流体的流动状态。
通过调整风洞中的气流速度、飞行器模型的姿态等参数,可以模拟不同飞行状态下的流体流动和飞行器性能,帮助工程师评估飞行器设计的稳定性、升阻比、气动特性等。
在这个案例中,流体和固体之间的流固耦合是通过相互作用来实现的。
流体的速度和压力分布会受到固体表面的细微变化影响,而固体的运动和力学性能则会受到流体的作用力和流动状况的限制。
通过对风洞实验的观测和数据分析,可以获取关于飞行器在不同飞行状态下的气动性能的重要信息,为改进飞行器设计、提高性能和安全性提供参考。
(完整word版)双向流固耦合实例Fluent与structure
![(完整word版)双向流固耦合实例Fluent与structure](https://img.taocdn.com/s3/m/73d1dd99a21614791611287f.png)
双向流固耦合实例(Fluent与structure)说明:本例只应用于FLUENT14.0以上版本。
ANSYS 14.0是2011年底新推出的版本,在该版本中,加入了一个新的模块System Coupling,目前只能用于fluent与ansys mechanical的双向流固耦合计算。
官方文档中有介绍说以后会逐渐添加对其它求解器的支持,不过这不重要,重要的是现在FLUENT终于可以不用借助第三方软件进行双向流固耦合计算了,个人认为这是新版本一个不小的改进。
模块及数据传递方式如下图所示。
一、几何准备流固耦合计算的模型准备与单独的流体计算不同,它需要同时创建流体模型与固体模型。
在geometry模块中同时创建流体模型与固体模型。
到后面流体模型或固体模块中再进行模型禁用处理。
模型中的尺寸:v1:32mm,h2:120mm,h5:60mm,h3:3mm,v4:15mm。
由于流体计算中需要进行动网格设置,因此推荐使用四面体网格。
当然如果挡板刚度很大网格变形很小时,可以使用六面体网格,划分六面体网格可以先将几何进行slice切割。
这里对流体区域网格划分六面体网格,固体域同样划分六面体网格。
二、流体部分设置1、网格划分双击B3单元格,进入meshing模块进行网格划分。
禁用固体部分几何。
设定各相关部分的尺寸,由于固体区域几何较为整齐,因此在切割后只需设定一个全局尺寸即可划分全六面体网格。
这里设定全局尺寸为1mm。
划分网格后如下图所示。
2、进行边界命名,以方便在fluent中进行边界条件设置设置左侧面为速度进口velocity inlet,右侧面为自由出流outflow,上侧面为壁面边界wall_top,正对的两侧面为壁面边界wall_side1与wall_side2(这两个边界在动网格设定中为变形域),设定与固体交界面为壁面边界(该边界在动网格中设定为system coupling类型)。
操作方式:选择对应的表面,点击右键,选择菜单create named selection,然后输入相应的边界名称。
【流体】Fluent双向流固耦合实例-竖板震荡仿真
![【流体】Fluent双向流固耦合实例-竖板震荡仿真](https://img.taocdn.com/s3/m/d341cfc03086bceb19e8b8f67c1cfad6195fe9ca.png)
【流体】Fluent双向流固耦合实例-竖板震荡仿真此案例是ANSYS自带帮助文档里,关于双向流固耦合仿真的例子,作为耦合仿真入门的案例,是挺不错的。
本文仿真软件:Transient Structural + Fluent案例描述:高1m,厚度0.06m的弹性板固定在地面上,在开始的0.5s时间内,对板一面施加100Pa的力,板子受力后弯曲。
然后撤销力,板子会回弹不断震荡。
四周是无风状态。
现在仿真此板子的受力运动过程引起附近空气的震荡,以及空气阻力对版子运动状态的影响。
一、Workbench平台搭建启动workbench软件,在软件左侧的Toolbox中调出三个模块到软件右侧的Project Schematic窗口中:Transient Structural ,Fluid Flow (Fluent)以及System Coupling。
它们之间的数据连接如下图所示。
二、固体力学仿真2.1 在workbench界面,双击A2 Engineering Data。
在打开的软件界面中,在A4单元格输入新材料名字“plane”,然后将左侧Toolbox的Density和Isotropic Elasticity两个属性用鼠标左键拖进A4单元格“plane”中,在软件正下方出现这两个参数设置。
将新建的plane材料设置为默认的固体材料。
右键A4单元格“plane”>“Default Solid Material For Model”。
然后关闭Engineering Data软件界面,返回workbench界面。
2.2 导入几何。
鼠标右键A3 Geometry >Import Geometry > Browse,打开“oscillating_plate.agdb”几何文件所在位置并导入。
几何文件在文末有下载链接。
然后双击打开A3 Geometry,进入Geometry软件界面。
生成几何并Suppress流体域“Fluid”。
ansys14workbench血管流固耦合分析实例
![ansys14workbench血管流固耦合分析实例](https://img.taocdn.com/s3/m/05c3459501f69e31423294ac.png)
Ansys14 workbench血管流固耦合实例根据收集的一些资料,进行学习后,试着做了这个ansys14workbench的血管流固耦合模拟,感觉能够耦合上,仅是熟悉流固耦合分析过程,不一定正确,仅供参考,希望大家多讨论。
谢谢!1、先在proe5中建立血管与血液流体区的模型(两者装配起来),或者直接在workbench中建模。
图1 模型图2、新建工程。
在workbench中toolbox中选custom system,双击FSI: FluidFlow(fluent)->static structure.图2 计算工程3、修改engineering data,因为系统缺省材料是钢,需要构建血管材料,如图3所示。
先复制steel,而后修改密度1150kg/m3,杨氏模量4.5e8Pa,泊松比0.3,重新命名,最后在主菜单中点击“update project”保存.图3 修改工程材料4、模型导入,进入gemetry模块,import外部模型文件。
图4 模型导入图5、进入FLUENT网格划分。
在workbench工程视图中的Mesh上点击右键,选择Edit…,如图5所示,进入网格划分meshing界面,如图6所示。
我们这里需要去掉血管部分,只保留血液几何。
图5 进入网格划分图6 禁用血管模型6、设置网格方法。
默认是采用ICEM CFD进行网格划分,设置方式如图7所示,截面圆弧边分为12份,纵截面的边均分为10份,网格结果如图8所示。
另外在这个界面中要设置边界的几何面,如inlet、outlet、symmetry图7 设置网格划分方式图8 最终出网格图9 边界几何7、进入fluent图10 进入fluent关闭mesh,回到fluent工程窗口,右键点击setup,选择edit…,进入fluent。
这里设置瞬态计算,流体为血液(密度1060,动力粘度0.004pas),入口压力波动(用profile输入),出口压力0Pa,采用k-e湍流模型。
fluent流固耦合传热算例
![fluent流固耦合传热算例](https://img.taocdn.com/s3/m/79f0e2fbc67da26925c52cc58bd63186bceb922d.png)
fluent流固耦合传热算例摘要:fluent 流固耦合传热算例I.引言- 简述流固耦合传热算例的重要性- 介绍fluent 软件在流固耦合传热计算中的应用II.fluent 软件介绍- 概述fluent 软件的特点和功能- 讲解fluent 软件在流固耦合传热计算中的操作流程III.流固耦合传热算例解析- 分析算例背景及目的- 详细描述算例的流固耦合传热计算过程- 解释算例结果及其意义IV.结论- 总结算例的流固耦合传热计算经验- 提出进一步研究和改进的建议正文:fluent 流固耦合传热算例I.引言流固耦合传热算例在工程领域中具有广泛的应用,可以帮助工程师们更好地理解和掌握流固耦合传热现象。
fluent 软件作为一种强大的流体动力学模拟软件,在流固耦合传热计算中具有重要的作用。
本文将通过一个具体的算例,详细介绍fluent 软件在流固耦合传热计算中的应用。
II.fluent 软件介绍fluent 软件是一款功能强大的流体动力学模拟软件,广泛应用于航空航天、汽车制造、能源等领域。
它具有丰富的物理模型和强大的数值计算能力,可以模拟流体流动、热传导、化学反应等多种物理现象。
在流固耦合传热计算中,fluent 软件可以实现流体与固体结构之间的热传递模拟,为工程师们提供准确的计算结果。
III.流固耦合传热算例解析为了具体阐述fluent 软件在流固耦合传热计算中的应用,我们选取了一个典型的算例进行详细分析。
算例背景为一组流固耦合传热实验,实验中涉及到流体流动、固体传热以及流固耦合传热现象。
我们使用fluent 软件对实验进行模拟,以获取流固耦合传热过程中的温度分布和热流密度等关键参数。
在fluent 软件的操作过程中,我们首先创建了流体和固体的几何模型,并定义了它们的材料属性。
接着,我们设置边界条件,包括流体进口、出口和固体表面的热交换条件。
在求解器设置中,我们选择了适用于流固耦合传热计算的求解器,并设置了相应的耦合条件。
ansysworkbench流固耦合计算实例
![ansysworkbench流固耦合计算实例](https://img.taocdn.com/s3/m/f90b4ca82e3f5727a4e96224.png)
Oscillating Plate with Two-Way Fluid-Structure InteractionIntroductionThis tutorial includes:« Features« Overview of the Problem to Solve«Setti ng up the Solid Physics in Simulatio n (ANSYS Workbe nch)«Setti ng up the Fluid Physics and ANSYS Multi-field Setti ngs in ANSYS CFX-Pre* Obta ining a Solution using ANSYS CFX-Solver Ma nager* Viewi ng Results in ANSYS CFX-PostIf this is the first tutorial you are working with, it is important to review the following topics before begi nning:«Sett ing the Worki ng Directory* Cha nging the Display ColorsUni ess you pla n on running a sessi on file, you should copy the sample files used in this tutorial from the in stallati on folder for your software (<CFXROOT>/examples/) to your work ing directory. This preve nts you from overwriti ng source files provided with your in stallatio n. If you pla n to use a sessi on file, please refer to Play ing a Sessi on File.Sample files refere need by this tutorial in clude:* Oscillati ngPlate.pre* Oscillati ngPlate.agdb* Oscillati ngPlate.gtm* Oscillati ngPlate.i np1. FeaturesIn this tutorial you will lear n about:* Moving mesh* Fluid-solid in teract ion (in cludi ng modeli ng solid deformati on using ANSYS)* Running an ANSYS Multi-field (MFX) simulatio n* Post-process ing two results files simulta neously.2. Overview of the Problem to SolveThis tutorial uses a simple oscillat ing plate example to dem on strate how to set up and run a simulation involving two-way Fluid-Structure Interaction, where the fluid physics is solved in ANSYS CFX and the solid physics is solved in the FEA package ANSYS. Coupling between the two solvers is required throughout the soluti on to model the in teract ion betwee n fluid and solid as time progresses, and the framework for the coupli ng is provided by the ANSYS Multi-field solver, using the MFX setup.The geometry con sists of a 2D closed cavity. A thin plate is an chored to the bottom of the cavity as show n below:An in itial pressure of 100 Pa is applied to one side of the thin plate for 0.5 sec onds in order to distort it. Once this pressure is released, the plate oscillates backwards and forwards as it attempts to regain its equilibrium (vertical) position. The surrounding fluid damps the oscillations, which therefore have an amplitude that decreases in time. The CFX Solver calculates how the fluid resp onds to the moti on of the plate, and the ANSYS Solver calculates how the plate deforms as a result of both the in itial applied pressure and the pressure result ing from the prese nee of the fluid. Coupli ng betwee n the two solvers is required si nee the solid deformati on affects the fluid soluti on, and the fluid solution affects the solid deformation.The tutorial describes the setup and execution of the calculation including the setup of the solid physics in Simulati on (withi n ANSYS Workbe nch) and the setup of the fluid physics and ANSYS Multi-field sett ings in ANSYS CFX-Pre. If you do n ot have ANSYS Workbe nch, the n you can use the provided ANSYS in put file to avoid the n eed for Simulatio n.3. Setting up the Solid Physics in Simulation (ANSYS Workbench)This secti on describes the step-by-step defi niti on of the solid physics in Simulati on with in ANSYS Workbe nch that will result in the creation of an ANSYS in put file Oscillati ngPlate.i np. If you prefer, you can in stead use the provided Oscillati ngPlate.i np file and continue from Sett ing up the Fluid Physics and ANSYS Multi-field Setti ngs in ANSYS CFX-Pre.Creating a New Simulatio n1. If required, lau nch ANSYS Workbe nch.2. Click Empty Project. The Project page appears displaying an unsaved project.3. Select File > Save or click Save butt on.4. If required, set the path location to a different folder. The default location is your workingdirectory. However, if you have a specific folder that you want to use to store files createdduring this tutorial, change the path.5. Un der File name, type Oscillat in gPlate.6. Click Save.7. Under Link to Geometry File on the left hand task bar click Browse. Select the provided fileOscillatingPlate.agdb and click Open .8. Make sure that OscillatingPlate.agdb is highlighted and click New simulation from the left-hand taskbar.Creati ng the Solid Material1. When Simulatio n ope ns, expa nd Geometry in the project tree at the left hand side of theSimulatio n win dow.2. Select Solid, and in the Details view below, select Material .3. Use the arrow that appears next to the material name Structural Steel to select NewMaterial .4. When the Engineering Data window ope ns, right-click New Material from the tree viewand ren ame it to Plate.-OlCdfatii'ngFLHr X_j| |2|4 PlMft□ %■ ShudijMl 咅 W浒P 窃A H - 5*np (n?d 二 j L OAd HrftC#Mh& IO]1PxopE 冲1 Iwmai 匚Cl WAn-TLLi专RCilM HiMi!卫E >leot r mnanEliL Add-'Aemove iPiaperiieRiFeme丄.1Fl ■任耐Q OlhtH m5. Enter 2.5e06 for Young's Modulus , 0.35 for Poisson's Ratio and 2550 for Density .Note that the other properties are not used for this simulati on, and that the un its for these values are implied by the global un its in Simulati on.6. Click the Simulation tab near the top of the Workbench window to return to the simulatio n. Basic An alysis Sett ingsThe ANSYS Multi-field simulation is a transient mechanical analysis, with a timestep of 0.1 s and a time duration of 5 s.1. Select New Analysis > Flexible Dynamic from the toolbar.2. Select An alysis Setti ngs from the tree view and in the Details view below, set Auto TimeStepping to Off. 3. Set Time Step to 0.1.OE ngrie^ii^ig D-al-s-]-占 ClgtLH H4. Under Tabular Data at the bottom right of the window, set End Time to5.0 for the Steps =1 sett in g.Inserting LoadsLoads are applied to an FEA an alysis as the equivale nt of boun dary con diti ons in ANSYS CFX. In this sect ion, you will set a fixed support, a fluid-solid in terface, and a pressure load.Fixed SupportThe fixed support is required to hold the bottom of the thin plate in place.1. Right-click Flexible Dynamic in the tree and select Insert > Fixed Support from the shortcutmenu.2. Rotate the geometry using the Rotate butt on so that the bottom (low-y) face of thesolid is visible, then select Face 囲and click the low-y face.That face should be highlighted to in dicate selecti on.3. Ensure Fixed Support is selected in the Outline view, then, in the Details view, selectGeometry and click 1 Face to make the Apply butt on appear (if n ecessary). Click Apply to set the fixed support.Fluid-Solid InterfaceIt is n ecessary to defi ne the regi on in the solid that defi nes the in terface betwee n the fluid in CFX and the solid in ANSYS. Data is excha nged across this in terface duri ng the executi on of the simulatio n.1. Right-click Flexible Dynamic in the tree and select Insert > Fluid Solid Interface fromthe shortcut menu.2. Using the same face-selection procedure described earlier, select the three faces of thegeometry that form the in terface betwee n the solid and the fluid (low-x, high-y and high-xfaces) by holding down <Ctrl> to select multiple faces. Note that this load is automaticallygive n an in terface nu mber of 1.Pressure LoadThe pressure load provides the in itial additi onal pressure of 100 [Pa] for the first 0.5 sec onds of the simulati on .It is defi ned using a step function.1. Right-click Flexible Dyn amic in the tree and select Insert > Pressure from the shortcutmenu.2. Select the low-x face for Geometry.3. In the Details view, select Magnitude , and using the arrow that appears, select Tabular(Time).4. Under Tabular Data , set a pressure of 100 in the table row corresponding to a time of 0.Note: The units for time and pressure in this table are the global units of [s] and [Pa], respectively.5. You now n eed to add two new rows to the table. This can be done by typi ng the new timeand pressure data into the empty row at the bottom of the table, and Simulation willautomatically re-order the table in order of time value. Enter a pressure of 100 for a timevalue of 0.499, and a pressure of 0 for a time value of 0.5.This gives a step function for pressure that can be see n in the chart to the left of the table.Writi ng the ANSYS In put FileThe Simulation settings are now complete. An ANSYS Multi-field run cannot be launched from with in Simulati on, so the Solve butt ons cannot be used to obta in a soluti on.1. In stead, highlight Solution in the tree, select Tools > Write ANSYS Input File and choose towrite the solution setup to the file OscillatingPlate.inp.2. The mesh is automatically gen erated as part of this process. If you want to exam ine it, selectMesh from the tree.3. Save the Simulation database, use the tab near the top of the Workbench window to return tothe Oscillating Plate [Project] tab, and save the project itself.4. Setting up the Fluid Physics and ANSYS Multi-field Settings in ANSYS CFX-PreThis section describes the step-by-step definition of the flow physics and ANSYS Multi-field settings in ANSYS CFX-Pre.Playing a Session FileIf you want to skip past these instructions and to have ANSYS CFX-Pre set up the simulationautomatically, you can select Session> Play Tutorial from the menu in ANSYS CFX-Pre, then run the session file: OscillatingPlate.pre. After you have played the session file as described in earlier tutorials under Playing the Session File and Starting ANSYS CFX-Solver Manager, proceed to Obtaining a Solution using ANSYS CFX-Solver Manager.Creating a New Simulation1. Start ANSYS CFX-Pre.2. Select File > New Simulation .3. Select General and click OK.4. Select File > Save Simulation As.5. Under File name, type OscillatingPlate.6. Click Save.Importing the Mesh1. Right-click Mesh and select Import Mesh .2. Select the provided mesh file, OscillatingPlate.gtm and click Open.Note:The file that was just created in Simulation, OscillatingPlate.inp, will be used as an input file for the ANSYS Solver.Setting the Simulation TypeA transient ANSYS Multi-field run executes as a series of timesteps. The Simulation Type tab is used both to enable an ANSYS Multi-field run and to specify the time-related settings for it (in the External Solver Coupling settings). The ANSYS input file is read by ANSYS CFX-Pre so that it knows which Fluid Solid Interfaces are available.Once the timesteps and time duration are specified for the ANSYS Multi-field run (coupling run), ANSYS CFX automatically picks up these settings and it is not possible to set the timestep and time duration independently. Hence the only option available for Time Duration is Coupling Time Duration, and similarly for the related settings Time Step and Initial Time.2. Apply the follow ing sett ingsTab Setting ValueBasic Settings External Solver Coupling > Option ANSYS MultiField External Solver Coupling > ANSYS Input FileOscillatingPlate.inp[a]Coupling Time Control > Coupling Time Duration > TotalTime5 [s]Coupling Time Control > Coupling Time Steps > Option TimestepsCoupling Time Control > Coupling Time Steps > Timesteps 0.1 [s]Simulation Type > Option TransientSimulation Type > Time Duration > Option Coupling Time Duration Simulation Type > Time Steps > Option Coupling Time Steps Simulation Type > Initial Time > Option Coupling Initial Time呵This file is located in your working directory.3. Click OK.Note:You may see a physics validation message related to the differenee in the units used in ANSYS CFX-Pre and the units con tai ned withi n the ANSYS in put file. While it is importa nt to review the units used in any simulation, you should be aware that, in this specific case, the message is not crucial as it is related to temperature un its and there is no heat tran sfer in this case. Therefore, this specific tutorial will not be affected by the physics message.Creat ing the FluidA custom fluid is created with user-specified properties.1. Click Material 因.2. Set the n ame of the new material to Fluid.3. Apply the follow ing sett ingsTab Setting ValueBasic Settings Option Pure Substance Thermodynamic State (Selected) Thermodynamic State > Thermodynamic State LiquidMaterial Properties Equation of State > Molar Mass 1 [kg kmol A-1] 1. Click Simulation Type4. Click OK.Creat ing the Doma inIn order to allow the ANSYS Solver to com muni cate mesh displaceme nts to the CFX Solver, mesh moti on must be activated in CFX.1. Right click Simulation in the Outline tree view and ensure that Automatic Default Domain isselected. A domain named Default Domain should now appear under the Simulati on bran ch.2. Double click Default Doma in and apply the followi ng sett ings3. Click OK.Creati ng the Boun dary Con diti onsIn addition to the symmetry conditions, another type of boundary condition corresponding with the in teract ion betwee n the solid and the fluid is required in this tutorial.Fluid Solid Exter nal Boun daryThe in terface betwee n ANSYS and CFX is defi ned as an exter nal boun dary in CFX that has its mesh displacement being defined by the ANSYS Multi-field coupling process.When an ANSYS Multi-field specification is being made in ANSYS CFX-Pre, it is necessary to provide the name and number of the matching Fluid Solid Interface that was created in Simulati on. Since the in terface nu mber in Simulati on was 1, the n ame in questi on is FSIN_1. (If the in terface nu mber had bee n 2, the n the n ame would have bee n FSIN_2, and so on.)On this bou ndary, CFX will se nd ANSYS the forces on the in terface, and ANSYS will sendback the total mesh displacement it calculates given the forces passed from CFX and the other defi ned loads.1. Create a new boun dary con diti on n amed In terface.2. Apply the follow ing sett ings3. Click OK.Symmetry Boun dariesSince a 2D representation of the flow field is being modeled (using a 3D mesh with one eleme nt thick ness in the Z direct ion) symmetry boun daries will be created on the low and high Z 2D regi ons of the mesh.1. Create a new boun dary con diti on n amed Sym1.2. Apply the follow ing sett ings3. Click OK.4. Create a new boun dary con diti on n amed Sym2.5. Apply the follow ing sett ings6. Click OK.Setting Initial ValuesSince a transient simulation is being modeled, initial values are required for all variables.3. Click OK .Setti ng Solver Con trolVarious ANSYS Multi-field sett ings are co ntain ed un der Solver Control un der the ExternalCoupling tab. Most of these sett ings do not n eed to be cha nged for this simulati on.With in each timestep, a series of “ coupli ng ” or “ stagger ” iterati ons are performed to ensure that CFX, ANSYS and the data excha nged betwee n the two solvers are all con siste nt. Within each stagger iteration, ANSYS and CFX both run once each, but which one runs first is a user-specifiable setting. In general, it is slightly more efficient to choose the solver that drives the simulation to run first. In this case, the simulation is being driven by the initial pressure applied inANSYS, so ANSYS is set to solve before CFX within each stagger iteratio n.1. Click Solver Control 空J .2. Apply the follow ing sett ings:1. Click Global Initialization3. Click OK.Setti ng Output Co ntrolThis step sets up transient results files to be written at set intervals.1. Click Output Control E3 .2. On the Trn Results tab, create a new transient result with the default name.3. Apply the follow ing sett ings to Tran sie nt Results 1:4. Click the Monitor tab.5. Select Monitor Options .6. Un der Monitor Points and Expressions:7. Click Add new item and accept the default name.8. Set Option to Cartesia n Coordin ates.9. Set Output Variables List to Total Mesh Displacement X.10. Set Cartesian Coordinates to [0, 1,0].11. Click OK.Writi ng the Solver (.def) File1. Click Write Solver File2. If the Physics Validation Summary dialog box appears, click Yes to proceed.3. Apply the follow ing sett ings4. Ensure Start Solver Manager is selected and click Save.5. If you are notified the file already exists, click Overwrite .6. This file is provided in the tutorial directory and will exist in your working folder if you have copied it there.7. Quit ANSYS CFX-Pre, savi ng the simulatio n ( .cfx) file at your discreti on.5. Obtaining a Solution using ANSYS CFX-Solver ManagerThe execution of an ANSYS Multi-field simulation requires both the CFX and ANSYS solvers to be running and com muni cat ing with each other. ANSYS CFX-Solver Man ager can be used to launch both solvers and to mon itor the output from both.1. En sure the Define Run dialog box is displayed.There is a new MultiField tab which contains settings specific for an ANSYS Multi-field simulatio n.2. On the MultiField tab, check that the ANSYS in put file location is correct (the location is recorded in the definitionfile but may need to be changed if you have moved files aroun d).3. On UNIX systems, you may n eed to manu ally specify where the ANSYS in stallati on is if it is not in the defaultlocati on. In this case, you must provide the path to the v110/a nsys directory.4. Click Start Run.The run begi ns by some in itial process ing of the ANSYS Multi-field in put which results in the creati on of a file containing the n ecessary multi-field comma nds for ANSYS, and the n the ANSYS Solver is started. The CFX Solver is then started in such a way that it knows how to commu ni cate with the ANSYS Solver.After the run is un der way, two new plots appear in ANSYS CFX-Solver Man ager:ANSYS Field Solver (Structural) This plot is produced only whe n the solid physics is set to use large displaceme nts or whe n other non-I in ear an alyses are performed. It shows con verge nee of the ANSYS Solver. Full details of the quantities are described in the ANSYS user documentation. In gen eral, the CRIT qua ntities are the con verge nce criteria for each releva nt variable, and the L2 qua ntities represe nt the L2 Norm of the releva nt variable. For con verge nce, the L2 Norm should be below the criteria. The x-axis of the plot is the cumulative iterati on nu mber for ANSYS, which does not correspond to either timesteps or stagger iterations. Several ANSYS iterations will be performed for each timestep, depe nding on how quickly ANSYS con verges. You will usually see a somewhat “ spiky ” plot, as each qua ntity will be uncon verged at the start of each timestep, and the n con verge nee will improve.ANSYS Inteface Loads (Structural) This plot shows the con verge nee for each qua ntity that is part of the data exchanged between the CFX and ANSYS Solvers. In this case, four lines appear, corresp onding to two force comp onents (FX and FY) and two displaceme nt comp onents (UX and UY). Since the an alysis is 2D, FZ and UZ are not excha nged. Each qua ntity is con verged when the plot shows a negative value. The x-axis of the plot corresponds to the cumulative nu mber of stagger iterati ons (coupli ng iterati ons) and there are several of these for every timestep. Aga in, aspiky plot is expected as the qua ntities will not be con verged at the start of a timestep.The ANSYS out file is displayed in ANSYS CFX-Solver Ma nager as an extra tab. Similar to the CFX out file, this is a text file recording output from ANSYS as the solution progresses.1. Click the User Points tab and watch how the top of the plate displaces as the solution develops.2. When the solvers have fini shed and ANSYS CFX-Solver Man ager puts up a dialog boxto tell you this, click Yes to post-process the results.3. If using Sta ndalo ne Mode, quit ANSYS CFX-Solver Man ager.6. Viewing Results in ANSYS CFX-PostFor an ANSYS Multi-field run, both the CFX and ANSYS results files will be opened up in ANSYS CFX-Post by default if ANSYS CFX-Post is started from a finished run in ANSYS CFX-Solver Man ager.Plotting Results on the SolidWhen ANSYS CFX-Post reads an ANSYS results file, all the ANSYS variables are available to plot on the solid, in cludi ng stresses and stra ins. The mesh regi ons available for plots by default are limited to the full boundary of the solid, plus certain named regions which are automatically created when particular types of load are added in Simulation. For example, any Fluid Solid In terface will have a corresp onding mesh regi on with a n ame such as FSIN 1. In this case, there is also a named region corresponding to the location of the fixed support, but in general pressure loads do not result in a n amed regi on.You can add extra mesh regi ons for plott ing by creat ing n amed select ions in Simulatio n - see the Simulation product documentation for more details. Note that the named selection must have a n ame which contains only En glish letters, nu mbers and un derscores for the n amed mesh regi on to be successfully created.Note that when ANSYS CFX-Post loads an ANSYS results file, the true global range for each variable is not automatically calculated, as this would add a substantial amount of time onto how long it takes to load such a file (you can turn on this calculati on using Edit > Options and using the Pre-calculate variable global ranges setting under CFX-Post > Files). When the global range is first used for plott ing a variable, it is calculated as the range with in the curre nt timestep. As subsequent timesteps are loaded into ANSYS CFX-Post, the Global Range is exte nded each time variable values are found outside the previous Global Ran ge.1. Tur n on the visibility of Bou ndary ANSYS (un der ANSYS > Domai n ANSYS).2. Right-click a blank area in the viewer and select Predefined Camera > View Towards -Z. Zoom into the plate tosee it clearly.3. Apply the followi ng sett ings to Bou ndary ANSYS:4. Click Apply.5. Select Tools > Timestep Selector from the task bar to open the Timestep Selector dialog box. Notice that aseparate list of timesteps is available for each results file loaded, although for this case the lists are the same. By default, Sync Cases is set to By Time Value which means that each time you cha nge the timestep for oneresults file, ANSYS CFX-Post will automatically load the results corresponding to the same time value for allother results files.6. Set Match to Nearest Available.7. Change to a time value of 1 [s] and click Apply.The corresp onding tran sie nt results are loaded and you can see the mesh move in both the CFX and ANSYS regio ns.1. Clear the visibility check box of Boun dary ANSYS.2. Create a con tour plot, set Locations to Boun dary ANSYS and Sym2, and set Variable to Total MeshDisplacement. Click Apply.3. Using the timestep selector, load time value 1.1 [s] (which is where the maximum total mesh displaceme ntoccurs).This verifies that the con tours of Total Mesh Displaceme nt are continu ous through both the ANSYS and CFX regio ns.Many FSI cases will have only relatively small mesh displacements, which can make visualization of the mesh displacement difficult. ANSYS CFX-Post allows you to visually magnify the mesh deformation for ease of viewing such displacements. Although it is not strictly n ecessary for this case, which has mesh displaceme nts which are easily visible unmagni fied, this is illustrated by the n ext few in struct ions.1. Using the timestep selector, load time value 0.1 [s] (which has a much smaller mesh displacement than thecurrently loaded timestep).2. Place the mouse over somewhere in the viewer where the backgro und color is show ing. Right-click and selectDeformation > Auto. Notice that the mesh displacements are now exaggerated. The Auto setting is calculated to make the largest mesh displacement a fixed perce ntage of the doma in size.3. To retur n the deformati ons to their true scale, right-click and select Deformation > True Scale.Creat ing an An imatio n1. Using the Timestep Selector dialog box, en sure the time value of 0.1 [s] is loaded.2. Clear the visibility check box of Con tour 1.3. Turn on the visibility of Sym2.4. Apply the followi ng sett ings to Sym2.5. Click Apply.6. Create a vector plot, set Locations to Sym1 and leave Variable set to Velocity. SetColor to be Constant and choose black. Click Apply.7. Select the visibility check box of Bou ndary ANSYS, and set Color to a con sta nt blue.8. The Animation dialog box appears.9. Select Keyframe Animation .10. In the Animation dialog box:a. Click New ^3 to create KeyframeNo1.b. Highlight KeyframeNo1, then change # of Frames to 48.c. Load the last timestep (50) using the timestep selector.d. Click New — to create KeyframeNo2.The # of Frames parameter has no effect for the last keyframe, so leave it at the default value. e. Select Save MPEG .the MPEG file. If the file path is not given, the file will be saved in the directory from which ANSYSCFX-Post was lau nched.g. Click Save.The MPEG file name (including path) will be set, but the MPEG will not be createdyet.h. Frame 1 is not loaded (The loaded frame is shown in the middle of theAnimation dialog box, beside F:). Click To Beginning to load it the n wait a few seconds for the frame to load.i. Click Play the animation — .The MPEG will be created as the animation proceeds. This will be slow, since atimestep must be loaded and objects must be created for each frame. To view theMPEG file, you n eed to use a viewer that supports the MPEG format.11. When you have finished, exit ANSYS CFX-Post. f.Click Browse next to the MPEG file data box to set a path and file name forClick An imation。
fluent流固耦合传热算例
![fluent流固耦合传热算例](https://img.taocdn.com/s3/m/2a57641bac02de80d4d8d15abe23482fb4da0239.png)
fluent流固耦合传热算例fluent流固耦合传热算例是针对流体和固体之间热量传递的一种数值模拟方法。
在工程领域中,流固耦合传热问题广泛存在于换热器、散热器、核电站等领域,对于优化设计、提高传热效率以及解决实际工程问题具有重要意义。
一、流固耦合传热概念介绍流固耦合传热是指在流体与固体之间由于温度差引起的热量传递过程。
在这种传热方式中,流体和固体的温度场、速度场以及压力场之间存在相互影响的关系。
流固耦合传热问题可以分为内部耦合和外部耦合两种类型。
内部耦合是指流体和固体内部的热量传递过程,而外部耦合是指流体和固体之间的热量交换。
二、流固耦合传热算例背景及意义本文以某实际工程为背景,通过fluent软件对流固耦合传热问题进行数值模拟。
旨在揭示流体与固体之间热量传递的规律,为实际工程提供参考依据。
通过分析算例,可以优化传热装置设计,提高传热效率,降低能耗,从而降低生产成本。
三、算例具体内容与分析本算例采用fluent软件进行数值模拟,考虑流体在固体内部的流动与热量传递。
模拟过程中,流体与固体的温度、速度、压力等参数随时间和空间的变化关系。
通过计算得到流体与固体之间的热量交换,从而分析传热过程的性能。
四、结果讨论与启示通过对流固耦合传热算例的分析,得到以下结论:1.在流固耦合传热过程中,流体的温度分布和速度分布对固体表面的热量传递有显著影响。
2.固体内部的温度分布存在一定的规律,可通过优化固体材料、改变流体流动方式等方法提高传热效果。
3.流固耦合传热问题具有较强的非线性特点,需要采用数值模拟方法进行深入研究。
本算例为实际工程提供了有益的参考,启示我们在设计传热装置时,要充分考虑流体与固体之间的相互作用,从而实现高效、节能的目标。
综上所述,fluent流固耦合传热算例对于揭示流体与固体之间热量传递规律具有重要的实际意义。
双向流固耦合实例
![双向流固耦合实例](https://img.taocdn.com/s3/m/85568b0be87101f69e31951a.png)
双向流固耦合实例(Fluent与structure)说明:本例只应用于FLUENT14.0以上版本。
ANSYS 14.0是2011年底新推出的版本,在该版本中,加入了一个新的模块System Coupling,目前只能用于fluent与ansys mechanical的双向流固耦合计算。
官方文档中有介绍说以后会逐渐添加对其它求解器的支持,不过这不重要,重要的是现在FLUENT终于可以不用借助第三方软件进行双向流固耦合计算了,个人认为这是新版本一个不小的改进。
模块及数据传递方式如下图所示。
一、几何准备流固耦合计算的模型准备与单独的流体计算不同,它需要同时创建流体模型与固体模型。
在geometry模块中同时创建流体模型与固体模型。
到后面流体模型或固体模块中再进行模型禁用处理。
模型中的尺寸:v1:32mm,h2:120mm,h5:60mm,h3:3mm,v4:15mm。
由于流体计算中需要进行动网格设置,因此推荐使用四面体网格。
当然如果挡板刚度很大网格变形很小时,可以使用六面体网格,划分六面体网格可以先将几何进行slice切割。
这里对流体区域网格划分六面体网格,固体域同样划分六面体网格。
二、流体部分设置1、网格划分双击B3单元格,进入meshing模块进行网格划分。
禁用固体部分几何。
设定各相关部分的尺寸,由于固体区域几何较为整齐,因此在切割后只需设定一个全局尺寸即可划分全六面体网格。
这里设定全局尺寸为1mm。
划分网格后如下图所示。
2、进行边界命名,以方便在fluent中进行边界条件设置设置左侧面为速度进口velocity inlet,右侧面为自由出流outflow,上侧面为壁面边界wall_top,正对的两侧面为壁面边界wall_side1与wall_side2(这两个边界在动网格设定中为变形域),设定与固体交界面为壁面边界(该边界在动网格中设定为system coupling类型)。
操作方式:选择对应的表面,点击右键,选择菜单create named selection,然后输入相应的边界名称。
fluent 流固耦合方法
![fluent 流固耦合方法](https://img.taocdn.com/s3/m/e5afc44bcd1755270722192e453610661ed95acf.png)
fluent 流固耦合方法Fluent coupling methods are a type of computational method used to simulate the interaction between fluids and solids. These methods are crucial in understanding the behavior of structures under fluid forces, and they have applications in various industries such as aerospace, automotive, and civil engineering. 流体和固体的相互作用对于结构的行为有着重要的影响,流体流固耦合方法可以很好地模拟这种相互作用,因此在航空航天、汽车和土木工程等行业有着广泛的应用。
One of the key challenges in developing fluent coupling methods is ensuring accuracy and computational efficiency. The interaction between fluids and solids is complex, and simulating it requires solving fluid dynamics equations and structural mechanics equations simultaneously. This often involves the use of iterative algorithms and requires careful consideration of the time scales and spatial scales of the problem. 发展流体流固耦合方法的一个关键挑战是确保准确性和计算效率,流体和固体的相互作用本身就很复杂,需要同时求解流体动力学方程和结构力学方程,这经常涉及使用迭代算法,并需要对问题的时间尺度和空间尺度进行仔细的考虑。
基于LS-DYNA及FLUENT的板壳结构流固耦合分析【精选】
![基于LS-DYNA及FLUENT的板壳结构流固耦合分析【精选】](https://img.taocdn.com/s3/m/55f71dd80408763231126edb6f1aff00bed57007.png)
基于LS-DYNA及FLUENT的板壳结构流固耦合分析本文采用ANSYS显示动力分析模块LS-DYNA及流场分析模块FLUENT,对水下的板壳结构运动及其界面的流固耦合现象进行了仿真分析。
流场计算得到的界面压强数据以外载荷的形式施加于结构表面,使其产生位移及变形;同时,结构的变化又进一步影响了流场的分布。
通过往复的双向耦合迭代,得到了板壳结构的动力学响应以及流场的分布情况。
仿真结果与试验结果的对比表明,此方法适用于解决兼有大位移及较大变形特征的流- 固耦合问题。
1 前言在自然界中,流-固耦合现象广泛存在于航空、航天、汽车、水利、石油、化工、海洋以及生物等领域。
很多实际问题中流体载荷对于结构的影响不可忽略;同时,结构的位移和变形也会对流场的分布产生重要影响。
例如各种水下运动机构都需要考虑这种现象。
板壳是基本的结构单元,研究其与流体相互作用的过程的仿真方法对水下结构的设计具有一定的指导意义。
文献利用ANSYS/LS-DYNA对板壳结构在水下爆炸冲击载荷作用下的动力学响应进行了仿真分析和试验研究,文献对窄流道中柔性单板流致振动引起的流-固耦合问题进行了数值模拟,但以上文献所进行的分析均为板壳结构处于约束状态下的平衡位置附近的振动耦合分析。
利用ANSYS静力学分析模块以及CFX或FLUENT等流体分析模块对有固定约束条件的板壳结构进行流-固耦合分析的实例已经很多,ANSYS Workbench中也有这方面的耦合实例。
但是对于流体冲击引起结构的大位移以及较大变形的动力学分析目前还不完善,有待进一步的研究。
因此本文应用大型通用有限元分析软件ANSYS13.0中的显示动力分析模块LS-DYNA以及流体分析模块FLUENT,对受流体冲击作用下兼有大位移及较大变形的板壳结构的流-固耦合作用进行了仿真分析。
2 有限元分析2.1 问题描述本文针对板壳结构受流体冲击载荷作用下的动力学响应进行分析,主要研究板壳结构的运动时间历程、应力分布规律以及对流场分布的影响。
ansys help流固耦合算例fluid_structure(内含解析)
![ansys help流固耦合算例fluid_structure(内含解析)](https://img.taocdn.com/s3/m/f0422729b4daa58da0114a62.png)
ansys help流固耦合算例fluid_structure(内含解析).txt这世界上除了我谁都没资格陪在你身边。
听着,我允许你喜欢我。
除了白头偕老,我们没别的路可选了什么时候想嫁人了就告诉我,我娶你。
/BATCH/COM,ANSYS RELEASE 12.1 UP20091102 13:06:05 10/24/2010/PREP7! /Batch,list/prep7/sho,gasket,grphshpp,offET,1,141 ! Fluid - static meshET,2,182, ! Hyperelastic element!!!!!!! Fluid Structure Interaction - Multiphysics!!!!!!! Deformation of a gasket in a flow field.!!!!!!!! Element plots are written to the file gasket.grph.!! - Water flows in a vertical channel through a constriction! formed by a rubber gasket.! - Determine the equilibrium position of the gasket and! the resulting flow field!! |! |! |----------| Boundary of "morphing fluid"! | ______! | |______ gasket! |! |----------| Boundary of "morphing fluid" (sf)! |!!! 1. Build the model of the entire domain:!! Fluid region - static mesh!!!! Gasket leaves a hole in the center of the channel!! Morphing Fluid region is a user defined region around!! the gasket. The fluid mesh here will deform and be!! updated as the gasket deforms.!!!! Parameterize Dimensions in the flow direction!!*SET,yent , 0.0 ! Y coordinate of the entrance to the channel*SET,dyen , 1.0 ! Undeformed geometry flow entrance length*SET,ysf1 , yent+dyen ! Y coordinate of entrance to the morphing fluid region*SET,dsf1 , 0.5 ! Thickness of upstream*SET,ygas , ysf1+dsf1 ! Y coordinate of the bottom of the gasket*SET,dg , 0.02 ! Thickness of the gasket*SET,dg2,dg/2.*SET,ytg , ygas+dg ! Y coordinate of the initial top of the gasket*SET,dsf2 , 0.5 ! Thickness of downstream region*SET,ysf2 , ytg + dsf2! Y of Top of the downstream morphing fluids region*SET,dyex , 6.0 ! Exit fluid length*SET,x , 0. ! Location of the centerline*SET,dgasr ,.20 ! Initial span of gasket*SET,piper , 0.3 ! Width of the analysis domain*SET,xrgap , piper-dgasr!! Width of completely unobtructed flow passage!!!!! Create geometry!!rect,xrgap,piper,ygas,ytg ! A1:Gasket (keypoints 1-4)rect,x,piper,ysf1,ysf2 ! A2: Morphing fluid regionrect,x,piper,yent,ysf1 ! A3: Fluid region with static meshrect,x,piper,ysf2,ysf2+dyex ! A4: Fluid region with static meshaovlap,allk,22,xrgap+dg2,ygas+dg2 !定义一个关键点为22号,坐标是x,y*SET,rarc , dg2*1.1larc,1,4,22,rarc !定义一个通过1,4点半径为dg2*1.1,圆心在22点这边的圆弧al,6,4 !定义一个由相关线围成的面adelete,7 !删除面7 adele,7al,6,3,22,7,8,5,21,1 !定义一个由相关线围成的面!!Mesh Division information*SET,ngap , 10 ! Number elements across the gap*SET,ngas , 10 ! Number of elements along the gasket*SET,rgas , -2 ! Spacing ratio along gasket*SET,nflu , ngap+ngas ! Number of elements across the fluid region*SET,raflu , -3 ! Space fluid elements near the walls and center*SET,nenty ,8 ! Elements along flow - entrance*SET,raent ,5 ! Size ratio in the inlet region*SET,nfl1 , 20 ! Elements along flow - first morph.fluid.*SET,nthgas , 4 ! Elements in the gasket*SET,nfl2 , 3 ! Elements along flow - second morph.fluid.*SET,next , 30 ! Elements along flow - exit region*SET,rext , 6 ! Size ratio in flow direction of outlet*SET,rafls , 12 ! Initial element spacing ratio - morph.fluidlesize,1,,,ngas,rgas !指定所选线上单元数线1上划分10个单元中间尺寸比两端尺寸=|-2|lesize,3,,,ngas,rgas !指定所选线上单元数线3上划分10个单元中间尺寸比两端尺寸=|-2|*SET,nfl11, nfl1*2+9lsel,s,,,2,4,2 ! (Modify lesize of line 8 if changing gasket mesh) 选择线从2号线递增到4号线每次递增2lesize,all,,,nthgasallslesize,5,,,nflu,raflulesize,7,,,nflu,raflulesize,9,,,nflu,raflulesize,15,,,nflu,raflulesize,18,,,nenty,1./raentlesize,17,,,nenty,1./raentlesize,21,,,nfl1,raflslesize,8,,,nfl11,-1./(rafls+3)lesize,22,,,nfl1,raflslesize,19,,,next,rextlesize,20,,,next,rext!!! AATT,MAT,REAL,TYPE - Set the attributes for the areasasel,s,,,1,2 !选择面从1号面递增到2号面每次递增1(默认)aatt,2,2,2 ! Gasket (material 2) 赋给选择的区域(点,面,线或体)2号材料属性,2号实常数,2号单元类型asel,s,,,3 !选择面3cm,area2,area !把选择的面名称定义为area2alist ! List area selected for further morphingasel,a,,,5,6 !在原来的基础上添选面2,3aatt,1,1,1 ! Fluid area (material 1)alls/eshape,2 !asel,u,,,2,3 !在当前已经选择的面中选面2,3amesh,all !划分已选择的面/eshape,0asel,s,,,2,3amesh,all!-----------------!!!!! Create element plot and write to the file gasket.grphasel,s,,,1,3 !选择面1,3esla,s !选择被选面上的单元点/Title, Initial mesh for gasket and neighborhood !命名标题eplot/ZOOM,1,RECT,0.3,-0.6,0.4,-0.5 !选择区域alls!-----------------!!!!!!! 2. Create Physics Environment for theFluid..................................................第二大步创建流体的物理环境et,1,141 !定义1号单元为141号材料单元et,2,0 ! Gasket becomes the Null Element定义2号单元为0号单元*SET,vin,3.5e-1 ! Inlet water velocity (meters/second)!! CFD Solution Control 计算流体力学求解控制flda,solu,flow,1flda,solu,turb,1flda,iter,exec,400flda,outp,sumf,10!! CFD Property Information 计算流体力学属性控制flda,prot,dens,constant !flda,prot,visc,constant !粘度系数flda,nomi,dens,1000. ! 1000 kg/m3 for density - water 密度flda,nomi,visc,4.6E-4 ! 4.6E-4 kg-s/m (viscosity of water) 粘性flda,conv,pres,1.E-8 ! Tighten pressure equation convergence 收敛判断?!! CFD Boundary Conditions (Applied to Solid Model) 计算流体力学中固体模型的边界条件lsel,s,,,8,17,9 !选择线8,17,9lsel,a,,,20 !添选线20dl,all,,vx,0.,1 ! Centerline symmetry 定义所选中的直线中的所有的直线的约束,x速度为0,直线的端点同样被作用lsel,s,,,9dl,all,,vx,0.,1dl,all,,vy,vin,1 ! Inlet Condition 入口条件lsel,s,,,2lsel,a,,,18,19lsel,a,,,21,22dl,all,,vx,0.,1 ! Outer Wall外围边界条件vx,vy为0dl,all,,vy,0.,1lsel,s,,,1,3,2lsel,a,,,6dl,all,,vx,0.,1 ! Gasket橡皮垫的vx,vy为0dl,all,,vy,0.,1lsel,s,,,15dl,15,,pres,0.,1 ! Outlet pressure condition出口压力条件压力为0!!! create named component of nodes at the bottom of gasketlsel,s,,,1 !选择线1nsll,,1 !选择所选择的线上的节点,包括关键点cm,gasket,node !把所选择的点定义为gasketnlist ! List initial nodal positions of the bottom of the gasket/com, +++++++++ STARTING gasket coordinates --------alls !选择所有的东东/title,Fluid Analysisphysics,write,fluid,fluid !把all element information写下来!!!!!!! 3. Create Physics Environment for the Structure ..........................................第三大步创建结构的物理环境!!physics,clear !从数据库清除所有的信息,但是不清除当前的physics文件,删除的信息:all material properties, solution options, load step options, constraint equations, coupled nodes, results, and GUI preference settings !SOLCONTROL, , , NOPL,et,1,0 ! The Null element for the fluid regionet,2,182 ! Gasket element - material 2keyopt,2,3,2 ! Plane stress 单元2的第3个选项为2 表面Z strain=0 平面应力状况keyopt,2,6,1 ! mixed u-Pkeyopt,2,1,2 ! Enhanced strainmp,nuxy,2,0.49967 ! Poisson's ratio for the rubber定义2号单元的泊松比为……tb,mooney,2 ! 数据表??tbdata,1,0.293E+6 ! Mooney-Rivlin Constants 在数据表的第一个表??tbdata,2,0.177E+6 ! " " "tb,hyper,2,,2,mooneytbdata,1,0.293E+6,0.177E+6, (1.0-2.0*0.49967)/(0.293E+6+0.177E+6)lsel,s,,,2 !选择线2nsll,,1 !选择所选择的线上的点,包括端点d,all,ux,0. !定义所有选择的点的x位移为0d,all,uy,0. ! Fix the end of the gasket定义所有选择的点的y位移为0alls/title,structural analysisfinish/solu !进入求解器antype,static !定义分析类型为静态求解nlgeom,on !在静态分析或完全瞬态分析中包含大变形效应cnvtol,f,,,,-1 !设置非线性分析的收敛值physics,write,struc,struc !把all element information写下来physics,clear !从数据库清除所有的信息,但是不清除当前的physics文件save !保存!!!!!!! 4. Fluid-Structure Interaction Loop ...................................................第四大步固流循环!!loop=25 ! Maximum allowed number of loops 定义最大循环次数为25toler=0.005 ! Convergence tolerance for maximum displacement 定义最大位移的收敛误差*dim,dismax,array,loop ! Define array of maximum displacement values 定义大小为25的名为dismax的矩阵*dim,strcri,array,loop ! Define array of convergence values 定义大小为25的名为strcri的矩阵*dim,index,array,loop ! 定义大小为25的名为index的矩阵*do,i,1,loop ! Execute fluid -> structure solutions do循环===============================================↓↓↓/solu !进入求解器...................................................................................|*↓*|physics,read,fluid ! Read in fluid environment 读取流体环境设置*if,i,ne,1,then !如果i不等于1,执行……|flda,iter,exec,100 ! Execute 100 global iterations for设置PLOTRAN分析中用到的参数 |if循环*endif ! each new geometry |solve ! FLOTRAN solution 流体分析完毕.............................................................|*↑*|fini! end of fluid portion 完成流体分析部分physics,read,struc ! Read in structures environment 读取结构环境设置/assign,esave,struc,esav ! Files for restarting nonlinear structure为下一步的结构分析分配文件/assign,emat,struc,emat*if,i,gt,1,then ! Structural restart loop 如果i>1,执行……|parsave,all ! Save parameters for convergence check 保存所有的参数|resume ! Resume DB - to return original node positions 恢复数据返回初始节点位置|parresume ! Resume parameters needed for convergence check 恢复所有的参数数据 |if循环/prep7 ! |antype,stat,rest !Restart the analysis. 重启分析|fini ! |*endif ! |/solu !......................................................... .......................................|*↓*| solc,offlsel,s,,,1,3,2 ! Select proper lines to apply fluid pressures 选择合适的线施加流体压力lsel,a,,,6 ! to the entire gasket surface 添选线6nsll,,1 ! 选择线上的点,包括端点esel,s,type,,2 ! 选择一簇单元,按照单元类型号,跨幅最大为2 ldread,pres,last,,,,,rfl ! Apply pressure surface load from Flotran读取流体面的压力结果文件作为结构分析的荷载条件sfelist !列表显示单元的面荷载alls rescontrol,,none ! Do not use multiframe restart for nonlinear !nsub,4,10,1 solve !结构分析完毕.....................................................................................|*↑*|*if,i,eq,1,then !如果i等于1,执行……................................|save ! save original node locations at the first run......|if循环*endif !....................................................|fini/post1cmsel,s,gasket !选择gsket(gasket见line160)nsort,u,sum,1,1 !设置列表顺序显示总位移按递增顺序按绝对值*get,dismax(i),sort,0,max ! Get the maximum displacement value 得到最大的位移值strcri(i)=toler*dismax(i) !初始化strcri矩阵第i个元素allsfini/prep7mkey=2 ! Select level of mesh morphing for fluiddamorph,area2, ,mkey ! Perform morphing of "morphing fluid",移动area2的节点,使其服从变形!----------------!!!!! Create element plot and write it in file gasket.grphfini/prep7et,1,42asel,s,,,1,3esla,s !选择被选择面上的节点/Title, EPLOT after DAMORPH,area2, ,%mkey% step number %i%eplot !Produces an element display of the selected elementsalls!-----------------cmsel,s,gasket !选择gsketnlist ! List updated coordinates of bottom of gasket for comparison显示节点/com, +++++++++ UPDATED gasket coordinates --------allsfini/assign,esav !为下一步的结构分析分配文件/assign,emat!!!! Checking convergence criteriaimax= iindex(i)=i*if,i,gt,1,thenstrcri(i)=abs(dismax(i)-dismax(i-1))-toler*dismax(i-1)*if,strcri(i),le,0,thenstrcri(i)=0*exit ! Stop looping if convergence is reached*endif*endif*enddo ! do循环===============================================↑↑↑!!!!! End of the Computational loopsave ! Nodal coordinates of deformed geometry are saved!!!!! Convergence printout*vwrite(/'Loop No. Max.Displacement Struct.Convergence')/nopr*vlen,imax*vwrite,index(1),dismax(1),strcri(1)(f7.0,2e17.4)finish!!!!! Postprocessing of the results!!! 1. Flotran results.physics,read,fluid/post1set,last/Title, Flotran: Streamlines Near Gasketplnsol,strm/Title, Flotran: Pressure Contoursplnsol,presfini!!! 2. Structural results.。
fluent二维流固耦合
![fluent二维流固耦合](https://img.taocdn.com/s3/m/eb152b5dcbaedd3383c4bb4cf7ec4afe04a1b182.png)
fluent二维流固耦合Fluent二维流固耦合引言:Fluent是一种流体力学模拟软件,广泛应用于工程领域。
流固耦合是指在流体力学模拟中,考虑固体物体与流体的相互作用。
本文将介绍Fluent中的二维流固耦合模拟,讨论其原理、应用以及相关注意事项。
一、二维流固耦合模拟的原理在Fluent中,二维流固耦合模拟是基于有限体积法和有限元法的耦合求解。
有限体积法用于求解流体的动力学方程,而有限元法用于求解固体的弹性方程。
通过迭代求解两个方程组,可以得到流体和固体的相互作用。
二、二维流固耦合模拟的应用1. 汽车空气动力学研究:二维流固耦合模拟可以用于分析汽车在行驶过程中的空气动力学特性,如阻力、升力等。
通过优化车身形状和空气动力学特性,可以提高汽车的燃油效率和稳定性。
2. 飞机结构研究:二维流固耦合模拟可以用于分析飞机在飞行过程中的结构响应,如飞机机翼的变形、应力分布等。
通过优化飞机的结构设计,可以提高飞机的飞行性能和安全性。
3. 建筑物抗风设计:二维流固耦合模拟可以用于分析建筑物在强风作用下的结构响应,如风荷载、振动等。
通过优化建筑物的结构设计和材料选择,可以提高建筑物的抗风能力和安全性。
4. 水力发电机组设计:二维流固耦合模拟可以用于分析水力发电机组在运行过程中的流体特性和固体结构响应,如水流分布、叶片变形等。
通过优化水力发电机组的设计和调整运行参数,可以提高发电效率和可靠性。
三、二维流固耦合模拟的注意事项1. 网格生成:在进行二维流固耦合模拟前,需要先生成合适的网格。
网格的质量对模拟结果有重要影响,应注意网格的精细度和光滑性。
2. 材料模型:在模拟中,需要选择合适的材料模型来描述固体的力学行为。
常用的材料模型有线性弹性模型、非线性弹性模型等,应根据实际情况选择合适的模型。
3. 边界条件:在模拟中,需要为流体和固体设置合适的边界条件。
边界条件的选择对模拟结果有重要影响,应根据实际情况设置合理的边界条件。
- 1、下载文档前请自行甄别文档内容的完整性,平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益,请联系客服反馈,我们会尽快为您处理(人工客服工作时间:9:00-18:30)。
双向流固耦合实例(Fluent与structure)
说明:本例只应用于FLUENT14.0以上版本。
ANSYS 14.0是2011年底新推出的版本,在该版本中,加入了一个新的模块System Coupling,目前只能用于fluent与ansys mechanical的双向流固耦合计算。
官方文档中有介绍说以后会逐渐添加对其它求解器的支持,不过这不重要,重要的是现在FLUENT终于可以不用借助第三方软件进行双向流固耦合计算了,个人认为这是新版本一个不小的改进。
模块及数据传递方式如下图所示。
一、几何准备
流固耦合计算的模型准备与单独的流体计算不同,它需要同时创建流体模型与固体模型。
在geometry模块中同时创建流体模型与固体模型。
到后面流体模型或固体模块中再进行模型禁用处理。
模型中的尺寸:v1:32mm,h2:120mm,h5:60mm,h3:3mm,v4:15mm。
由于流体计算中需要进行动网格设置,因此推荐使用四面体网格。
当然如果挡板刚度很大网格变形很小时,可以使用六面体网格,划分六面体网格可以先将几何进行slice切割。
这里对流体区域网格划分六面体网格,固体域同样划分六面体网格。
二、流体部分设置
1、网格划分
双击B3单元格,进入meshing模块进行网格划分。
禁用固体部分几何。
设定各相关部分的尺寸,由于固体区域几何较为整齐,因此在切割后只需设定一个全局尺寸即可划分全六面体网格。
这里设定全局尺寸为1mm。
划分网格后如下图所示。
2、进行边界命名,以方便在fluent中进行边界条件设置
设置左侧面为速度进口velocity inlet,右侧面为自由出流outflow,上侧面为壁面边界wall_top,正对的两侧面为壁面边界wall_side1与wall_side2(这两个边界在动网格设定中为变形域),设定与固体交界面为壁面边界(该边界在动网格中设定为system coupling类型)。
操作方式:选择对应的表面,点击右键,选择菜单create named selection,然后输入相应的边界名称。
注意:FLUENT会自动检测输入的名称以使用对应的边界类型,当然用户也可以在fluent进行类型更改。
完成后的树形菜单如下图所示。
本部分操作完毕后,关闭meshing模块。
返回工程面板。
3、进入fluent设置
FLUENT主要进行动网格设置。
其它设置与单独进行FLUENT仿真完全一致。
设置使用瞬态计算,使用K-Epsilon湍流模型。
这里的动网格主要使用弹簧光顺处理(由于使用的是六面体网格且运动不规律),需要使用TUI命令打开光顺对六面体网格的支持。
使用命令
/define/dynamic-mesh/controls/smoothing-parameters。
动态层技术与网格重构方法在六面体网格中失效。
因此,建议使用四面体网格。
我们这里由于变形小,所以只使用光顺方法即可满足要求。
点击Dynamic mesh进入动网格设置面板。
如下图所示,激活动网格模型。
4、smoothing参数
使用弹簧光顺方法。
设置参数弹簧常数0.6,边界节点松弛因子0.6。
如下图所示。
5、运动区域设置
主要包括三个运动区域:流固耦合面、两侧的面。
其中流固耦合面运动方式为system coupling,两侧壁面运动类型为deforming。
设置最小网格尺寸0.8,最大网格尺寸1.5,最大扭曲率0.6。
如下图所示(点击查看大图)。
6、其它设置
包括求解控制参数设置、动画设置、自动保存设置、初始化设置、计算时间步及步长设置等。
与单独FLUENT使用没有任何差异。
迭代参数设置如下图所示。
关闭FLUENT,返回工程面板。
二、固体部分设置
1、材料设置
双击C2单元格进入固体材料设置。
这里保持默认的结构钢。
弹性模量2.1e11Pa,泊松比0.3。
需要注意的是材料特性决定了变形,因此对于刚度小的材料可能会存在大的位移,在流体求解器中动网格设置时需要加以关注。
点击retrun to project回到工程面板。
2、网格划分及进行约束
双击C4单元格进入固体网格划分模块。
设定网格尺寸1mm划分网格。
添加流固耦合面及固定边界约束。
设置分析参数,时间步长设置为0.01s,总时间为1s。
如下图所示。
设置完毕后,关闭DS返回工程面板。
右键单击C5单元格,选择update进行更新。
三、System Coupling设置
1、设置时间耦合
双击D2单元格,进入System Coupling面板。
点击Analysis Settings,如左下图所示。
在弹出的面板中设置end time为1s,设置step size为0.01s,如右上图所示。
2、设置耦合面
点选ctrl的同时选择固体与流体中的耦合面名称,点击右键,创建流固耦合面。
如下图所示。
点击Co-Sim. sequence单元格,在弹出的编辑面板中设置各求解器的启动顺序。
设置fluent为1,Transient为2。
如下图所示。
3、进行流固耦合计算
通过点击工具栏上的Update Project按钮进行流固耦合计算。